1. Field of Invention
This invention relates to an ink cartridge and an inkjet recording apparatus equipped with the ink cartridge.
2. Description of Related Art
An ink cartridge is typically loaded into an inkjet recording apparatus by mounting the ink cartridge into the inkjet recording apparatus. A rubber stopper is attached to the ink cartridge and prevents air, ink or any other material from entering or exiting the ink cartridges. The inkjet recording apparatus includes a hollow needle with an acuminate tip. When the ink cartridge is pushed and loaded into the inkjet recording apparatus, the hollow needle penetrates the stopper plug by which an inside of the ink cartridge is in communication with the hollow needle in order to supply ink to the inkjet recording apparatus. However, the acuminate tip of the hollow needle is formed with the acuminate tip projecting toward the user. It is thus necessary to secure a safety measure in order to prevent a user from touching the tip.
In Japanese Unexamined Patent Application Publication H3-197052, for example, an inkjet recording apparatus is equipped with a protection device that protects the user from the hollow needle when the hollow needle is exposed. The protection device has a protection plate installed between the hollow needle and a side in which the ink cartridge is inserted in order to cover the hollow needle. When the ink cartridge is loaded, a lock of the protection plate when in a shielding position is released and the hollow needle is exposed. Furthermore, the hollow needle penetrates the stopper plug and the ink cartridge is thus loaded in the inkjet recording apparatus. Furthermore, when the ink cartridge is removed, the protection plate is placed in the shielding position by a twisted coil spring and held at that position by a lock component. Thus, the protection plate shields the user from touching the hollow needle.
As disclosed in Japanese Unexamined Patent Application No. 2001-113723, there also exists ink cartridges that prevent ink from leaking from the cartridges when the cartridges are removed from inkjet recording devices. Such ink cartridges are provided with an ink chamber that stores ink, an ink supply port that externally supplies ink stored in the ink chamber, and an ink guidance chamber formed between the ink chamber and the ink supply port.
The ink guidance chamber houses a valve unit, and a cylindrical packing is inserted into the ink supply port. The valve unit is urged by a compression spring in a direction elastically contacting the cylindrical packing in order to obstruct the ink flow path, and the valve unit prevents ink from leaking from the ink chamber side. The ink cartridge is structured such that, when attached to an inkjet recording device, an ink supply needle penetrates the cylindrical packing and opposes the urging force of the compression spring to press the valve unit toward the ink chamber. An ink flow path is thereby formed in order to supply ink.